Garden tool sharpener

ABSTRACT

A sharpener for sharpening garden tools and the like comprises an elongated member having an elongated, generally planar body portion. A notch is formed intermediate the length of one of the side margins which define the longitudinal axis of the body portion, the notch having sidewall portions diverging outwardly from the base thereof. The elongated member has flanges along at least portions of the side margins of the body portion to either side of the notch so as to provide surfaces for manually gripping the sharpener during use thereof. A sharpening bit is detachably mounted on the body portion of the elongated member with a portion thereof extending over the notch base so as to be exposed for contact with a tool inserted in the notch. With the sharpening bit so mounted both surfaces of a tool defining a cutting edge may be sharpened by contact with the overlying portion of the sharpening bit without requiring reversal of either the tool or the sharpener.

Cite States atent [191 Stoutenberg 1 GARDEN TQOL SHARPENER [75] Inventor: Carl Christian Stoutenberg, Avon,

[21] Appl. No.: 321,862

[52] US. Cl 76/82, 51/173, 51/205 [51] Int. Cl 321k 11/00 [58] Field of Search 76/822, 82.1, 82; 51/205,

[56] References Cited UNlTED STATES PATENTS 2,451,203 10/1948 De Tray 76/822 2,800,040 7/1957 Triebes et al. 76/822 Primary Examiner-Andrew R. Juhasz Assistant ExaminerWilliam R. Briggs 1 June 4,1974

1 ABSTRACT A sharpener for sharpening garden tools and the like comprises an elongated member having an elongated, generally planar body portion. A notch is formed intermediate the length of one of the side margins which define the longitudinal axis of the body portion. the notch having sidewall portions diverging outwardly from the base thereof. The elongated member has flanges along at least portions of the side margins of the body portion to either side of the notch so as to provide surfaces for manually gripping the sharpener during use thereof. A sharpening bit is detachably mounted on the body portion of the elongated member with a portion thereof extending over the notch base so as to be exposed for contact with a tool inserted in the notch. With the sharpening bit so mounted both surfaces of a tool defining a cutting edge may be sharpened by contact with the overlying portion of the sharpening bit without requiring reversal of either the tool or the sharpener.

8 Claims, 6 Drawing Figures GARDEN TOOL SHARPENER BACKGROUND OF THE INVENTION To be truly versatile, a garden tool sharpener should be capable of use by both left and right handed persons with equal facility. Such sharpeners should be capable of being employed to sharpen both i of the surfaces which define the cutting edge of a tool without requiring the tool to be reversed relative to the sharpener.

Such versatility is generally not to be found embodied in existing sharpeners which, most commonly, are

provided with relatively elaborate flange guides that have been designed for use in sharpening a particular type of too]. As a result, it is normally necessary when employing sharpeners embodying such flange guides that, after one of the pair of surfaces which define the cutting edge of the tool has been sharpened, the tool must be rotated 180 relative to the sharpener in order to enable the other of the surfaces defining the cutting edge to be sharpened.

Another disadvantage of existing forms of sharpeners which is at least partially traceable to the type of flange guide embodied therein is that, although designed to be held by the users two hands when being utilized, such sharpeners too readily permit use thereof employing I from the fact that manyof the existing forms of sharp- I eners have been provided with gripping surfaces which are too easily capable of being grasped in one hand.

In order to provide the long life desired for a sharpener, it is conventional practice to provide the latter with a sharpening bit formed of tungsten carbide, a relatively expensive material. It has been found however, that a tungsten carbide bit is relatively brittle when placed under a bending load and as such will easily fracture unless provided with adequate support therefor. Therefore, it is important that any modifications which are made in the design of a sharpener in order to provide the latter with the desired degree of versatility discussed above be achieved without sacrificing support for the bit.

The use of a hardened bit in a tool for sharpening different items is disclosed in such varied prior art patents 2,800,040 issued July 23, 1957; and R.S.W. Lindsay- US. Pat. No. 3,293,949 issued Dec. 27, 1966. However, sharpeners of these types have not been found to perform entirely satisfactorily when actually utilized for purposes of sharpening various forms of garden tools such as grass shears, hedge shears, lawn mower blades, etc.

Accordingly, an object of the present invention is to provide a novel and improved garden tool sharpener with versatility for use by left and right handed users with equal facility and for permitting bothof the surfaces which define the cutting edge of the tool to be sharpened thereby without requiring the position of the tool to be reversed relative to the sharpener.

It is also an object of the present invention to provide such a sharpener having a pair of spaced gripping surfaces which require, for proper utilization of the sharpener, grasping by both hands of the user.

It is a further object of the present invention to provide such a sharpener which utilizes a tungsten carbide bit element and is provided with a body portion, on which the bit element is mounted, affording adequate support to the bit element so as to reduce the chance of fracture thereof.

Another object of the present invention is to provide such a sharpener which is easy to employ, is durable in operation, and yet is relatively inexpensive to manufac- SUMMARY OF THE INVENTION It has now been found that the foregoing and related objects can be readily attained in a sharpener for sharpening garden tools and the like which comprises an elongated member having an elongated, generally planar body. One of the side margins which define the longitudinal axis of the body portion of the elongated member has a notch formed therein intermediate the length thereof. In addition, the elongated member has flanges provided along at least portions of the side margins of the body portion to either side of the notch so as to provide surfaces for manually gripping the sharpenerduring use thereof. The sharpener also has a sharpening bit and means detachably mounting the sharpening bit on the body portion with a portion thereof extending over the notch base so as to be exposed for contact with a tool inserted in the notch. By so positioning the sharpening bit both surfaces of a tool defining a cutting edge may be sharpened by contact I with the overlying portion of the sharpening bit without requiring reversal of either the tool or the sharpener.

In accordance with the preferred embodiment of the invention, the notch is generally V-shaped in configuration, is formed in the body portion adjacent the center thereof and has sidewall portions diverging outwardly from the notch base to form an included angle of about to The elongated member has a pair of flanges along each of the side margins and the flanges of each pair are disposed on opposite sides of the notch. In addition, the pairs of flanges on opposite side margins are generally in alignment along the length of the body portion. Further, the sharpening bit is generally polygonal in configuration and the adjacent surface of the body portion defines a recess of complimentary configuration for receiving the bit. The sharpening bit has its outer side surface extending parallel to the longitudinal axis of the body portion and intersecting a substantially equal length of each of the notch sidewall portions. Finally, the detachable mounting means ineludes threaded fastening means seated in the sharpening bit and in a threaded aperture in the body portion adjacent the notch.

Such terms of reference as trailing, leading, upper and lower in the specification and claims are intended merely as terms to relate portions of the device with one another, and not as terms of limitation as to the orientation of the device, it being understood that the bit is disposed adjacent the forward edge of the upper surface.

BRIEF DESCRIPTION OF THE DRAWING FIG. 3 is an end elevational view thereof;

FIG. 4 is a fragmentary bottom view thereof;

FIG. 5 is an exploded fragmentary view in perspective of the fastener, the bit element and the body portion of the sharpener; and

FIG. 6 is a perspective view illustrating the sharpener in use by a person to sharpen a pair of shears clamped in a vise, only portions of the hands of the person being illustrated.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The elongated handle member 14 has an intermediate portion generally designated by the numeral and wing portions extending therefrom and generally designated by the numerals 18, 18'. Each of the wings or finger grip portions 18, 18' has a web portion 22 with its leading side edge outwardly receding towards the ends thereof relative to the longitudinal axis of the handle member 14 and with a trailing edge generally parallel to the longitudinal axis. Uptumed flanges 26 and 24 are provided along the side margins of the leading and trailing edges, respectively, of the web portions 22, and these flanges are inclined outwardly therefrom. The wing portions 18, 18' terminate at their ends in semicircular tab portions 28 having an aperture 30 extending therethrough by which the sharpener may be hung on a nail, peg or the like.

The intermediate portion 20 of the handle member 14 is of lesser width than the wing portions 18, 18 so that its trailing edge margin is inset from the trailing edge margins of the wing portions I8, 18. An upstanding flange 32 is provided along the trailing edge intermediate its ends and is spaced from the flanges 24 of the wing portions 18, 18' to provide generally V- shaped guide channels 33, for a purpose to be described more fully hereinafter. The forward or leading edge 44 is formed with a wide notch at its midpoint and generally designated by the numeral 40. As seen best in FIGS. 4 and 5, the notch has a generally V-shaped inner portion defined by the base 43 and the diverging leg portions 42, 42, and the bisector or axis of the notch extends substantially perpendicularly to the longitudinal axis of the handle member 14.

Adjacent the leading edge 44 the intermediate portion 20 is deformed to provide a recess 36 in the upper surface thereof dimensioned and configured to snugly seat the lower portion of the trailing and side edges of the bit element 12, which extends beyond the base 43 of the notch 40 so that its leading edge intersects the legs 42, 42' thereof. The bit element 12 and the intermediate portion 20 have aligned apertures 39, 41 respectively which seat the self-tapping threaded fastener 16. In this manner, the bit element 12 may be secured firmly to the handle member 14 against relative rotation.

With the sharpening bit element 12 seated within the recess 36, at least 75 percent of its lower surface area is supported by the handle member 14. The unsupported lower surface area of the sharpening area of the sharpening bit element 12 extending outwardly over the base 43 of the notch 40 is supported at its sides and rear with the plane of the forward edge of the sharpening bit element 12 symmetrically truncating the included angle formed by the notch 40 in a symmetrical fashion so that equal lengths of legs 42, 42 are dis- 4 posed directly underneath sharpening bit element 12.

The proper use of the sharpener 10 is indicated in FIG. 6 where a-grass shears blade to be sharpened is firmly secured in a vise 52 attached to a table 54 with the cutting edge portion of the blade 50 extending over the top of the vise 52. The sharpener 10 is held by a user in both hands, generally designated by the numeral 56, with the thumb 58 of each hand being placed against the surface of the associated finger grip or wing portion 18 between the flanges 24, 26 thereof and one or more of the remaining fingers 60 grasping the opposite surface of the associated finger grip portion 18. The finger grip flanges 24, 26 not only provide working surfaces against which the thumbs 58 can press, but also provide protection for the thumbs 58 in case the sharpener l0 slips during use. The flanges 24, 26 also remind the user to use two hands by digging into the palm of one attempting to, grab a finger grip portion 18 incorrectly.

The sharpener 10 is positioned relative to blade 50 with the bit 12 and the surface between the flanges generally facing the blade cutting edge 50' and handle 62, and with the leading edge of the sharpening bit element 12 contacting the blade edge 50 to be sharpened as far up the blade edge 50' towards the tool handle 62 as is possible. The sharpener may then be tilted slightly clockwise or counter-clockwise in a vertical plane so as to cause the leading bit edge to be flush with the bevel to be ground. The sharpener 10 is pitched toward the user at a 30 to 40 angle to the cutting edge 50 which will normally be horizontal. The blade 51 which is not being sharpened will generally fit in oneof the guides 33 to enable the sharpener 10 to be placed further along the blade 50 towards tool handle 62 than would otherwise be possible and furthermore to help maintain proper orientation of the sharpener 10 relative to blade 50 during sharpening thereof. The sharpener 10 is then repeatedly drawn towards the user with light easy strokes until the blade edge 50' is sharp. The trailing flange 32 will tend to deflect downwards any material being abraded from blade 50, thereby protecting the user. To sharpen both surfaces defining the cutting edge, the tilt of the bit is appropriately changed midway through the sharpening process without any reversal of the sharpener or tool relative to one another. When one blade is thoroughly sharpened, it may be deburred and given a final honingwith an appropriate stone such as an aluminium oxide stone and the tool may then be removed from the vise. It will be recognized that simultaneous maintenance of the correct positioning, tilt and pitch of the sharpener with less than two hands is nearly impossible, thus requiring the user to employ both hands.

It will be noted that due to the tilt of the sharpener 10 during the sharpening process, only the lower half of the leading side edge of the sharpening bit element 12 is abraded by blade 50. If the lower half of leading side 44 being used should become worn, screw 16 may temporarily loosened sufficiently to permit escape of sharpening bit element 12 from the depression 36 and rotation of the sharpening bit element 12 so as to present a new edge across notch 40. When all of the sides of the lower half become worn, screw 16 may be removed, the sharpening bit element 12 turned over and screw 16 once again fastened through the sharpening bit element 12 and the handle member 14. In this manner four new surfaces aremade available for sharpening so that the single square bit element 12 in effect presents eight usable sharpening surfaces.

As can be seen, the handle member is formed readily and easily from metal sheet stock in stamping and punching operations to form the notches, flanges and recess and the apertures therein may be punched or drilled. Preferably, the metal is provided with an electrodeposited coating to resist corrosion and provide an attractive appearance, metals such as nickel, chromium, zinc and cadmium being suitable therefore. Alternatively, the handle member may be cast from metal, or it may be molded from a durable, wear resistant synthetic plastic such as polyamide, polyacetal, or the like.

The cutting bit element is formed from any of the conventional wear resistant abrasive materials including tungsten carbide, silicon carbide and refractory metal oxides. Tungsten carbide is preferred for its long lasting characteristics.

The notch formed in the forward or leading edge of the handle member should be positioned adjacent the midpoint of its length for greatest control during sharpening with the sharpener tilted in either direction relative to the blade being sharpened. Its configuration may vary from that illustrated but it should have a generally V-shaped base portion providing diverging legs or sides to permit contact of the blade with the bit in either direction of tilt. The included angle defined by the generally V-shaped base portion will be about 70-l00 and perferably about 80-90 as shown.

Thus it can be seen from the foregoing detailed description and drawing that the novel garden tool sharpener of the present invention provides a handle member which can be used with equal facility by right and left handed persons and which may be utilized to sharpen right and left hand ground surfaces of a cutting edge without reversal of the sharpener relative to the blade being sharpened. Furthermore, in addition to providing a pair of thumb-engaging finger'grips, the handle member is of a configuration such that effective operation of the sharpener with a single hand is extremely uncomfortable, if not physically impossible, so that the opportunities for free hand accidents are severely reduced. Finally, the novel sharpener permits the use of an extremely small sharpening bit and provides a high degree of support against bending for the sharpening bit, so that the sharpening bit may be economically made from such long-lived, but brittle and expensive abrasive materials as tungsten carbide. Moreover, the novel sharpener may be manufactured readily and it is easy to employ and durable in use.

Having thus described the invention, 1 claim:

1. A sharpener for sharpening garden tools and the like comprising:

a. an elongated member having an elongated, generally planar body portion and having a pair of side margins which define the longitudinal axis thereof and a notch formed intermediate the length of one of said side margins, said notch having sidewall portions diverging outwardly from the base thereof and its axis extending substantially perpendicularly to said longitudinal axis defined by said side margins of said elongated member, said elongated member having longitudinally extending flanges along at least portions of the side margins of said 7 body portion to' either side of said notch and providing surfaces for manually gripping the sharpener during use thereof;

b. a sharpening bit; and

c. means detachably mounting said bit on one surface of said body portion thereof extending over said notch base and only a portion of the depth of said notch to provide a surface spaced from the base of said notch and extending substantially parallel to said longitudinal axis of said elongated member, said surface being exposed for contact with a tool inserted in said notch, said notch and bit being cooperatively dimensioned to permit either side sur face of a blade edge inserted into said notch to be brought into contact with a surface of said bit extending generally parallel to said longitudinal axis of said elongated member, whereby both side surfaces of a tool defining a cutting edge may be sharpened by contact with said overlying portion of said sharpening bit without requiring reversal of either the tool or the sharpener.

2. The sharpener of claim 1 wherein said notch is generally V-shaped in configuration, is formed in said body portion adjacent the center thereof, and has sidewall portions diverging outwardly from said notch base to form an included angle of about to 3. The sharpener of claim 1 wherein said elongated member has a pair of flanges along each of said side margins and the flanges of each said pair are disposed on opposite sides of said notch.

4. The sharpener of claim 3 wherein the pairs of flanges on opposite side margins are generally in alignment along the length of said body portion.

5. The sharpener of claim 1 wherein said detachable mounting means includes threaded fastening means seated in said sharpening bit and in a threaded aperture in said body portion adjacent said notch.

6. The sharpener of claim 1 wherein said sharpening bit is generally polygonal in configuration and wherein said one surface of said body portion defines a recess of complementary configuration in which said sharpening bit is seated, said recess preventing inadvertent rotation of said bit.

7. A sharpener for sharpening garden tools and the like comprising:

a. an elongated member having an elongated generally planar body portion and having a pair of side margins which define the longitudinal axis thereof and a notch formed intermediate the length of one of said side margins, said notch being of generally V-shaped configuration with sidewall portions diverging outwardly from the base thereof and its axis extending substantially perpendicularly to said longitudinal axis defined by said side margins of said elongated member, said base being disposed adjacent the midpoint of said longitudinal axis, said elongated member having a pair of upstanding and longitudinally extending flanges along each of said side margins, the upstanding flanges of said flange pair being disposed on opposite sides of said notch and the flange pairs on opposite side margins being generally in alignment along the length of said body portion;

b. a sharpening bit of generally polygonal configuration; and

c. a fastener seated in said sharpening bit and in an aperture in said body portion adjacent said notch mounting said sharpening bit on one surface of said axis of said elongated member; whereby both side surfaces of a tool defining a cutting edge may be sharpened by contact with said overlying side without requiring reversal of either the tool or the sharpener.

8. The sharpener of claim 7 wherein said flanges are generally upwardly turned relative to said body portion and said sharpening bit is mounted on the upper sur- 10 face of said body portion. 

1. A sharpener for sharpening garden tools and the like comprising: a. an elongated member having an elongated, generally planar body portion and having a pair of side margins which define the longitudinal axis thereof and a notch formed intermediate the length of one of said side margins, said notch having sidewall portions diverging outwardly from the base thereof and its axis extending substantially perpendicularly to said longitudinal axis defined by said side margins of said elongated member, said elongated member having longitudinally extending flanges along at least portions of the side margins of said body portion to either side of said notch and providing surfaces for manually gripping the sharpener during use thereof; b. a sharpening bit; and c. means detachably mounting said bit on one surface of said body portion thereof extending over said notch base and only a portion of the depth of said notch to provide a surface spaced from the base of said notch and extending substantially parallel to said longitudinal axis of said elongated member, said surface being exposed for contact with a tool inserted in said notch, said notch and bit being cooperatively dimensioned to permit either side surface of a blade edge inserted into said notch to be brought into contact with a surface of said bit extending generally parallel to said longitudinal axis of said elongated member, whereby both side surfaces of a tool defining a cutting edge may be sharpened by contact with said overlying portion of said sharpening bit without requiring reversal of either the tool or the sharpener.
 2. The sharpener of claim 1 wherein said notch is generally V-shaped in configuration, is formed in said body portion adjacent the center thereof, and has sidewall portions diverging outwardly from said notch base to form an included angle of about 70* to 100*.
 3. The sharpener of claim 1 wherein said elongated member has a pair of flanges along each of said side margins and the flanges of each said pair are disposed on opposite sides of said notch.
 4. The sharpener of claim 3 wherein the pairs of flanges on opposite side margins are generally in alignment along the length of said body portion.
 5. The sharpener of claim 1 wherein said detachable mounting means includes threaded fastening means seated in said sharpening bit and in a threaded aperture in said body portion adjacent said notch.
 6. The sharpener of claim 1 wherein said sharpening bit is generally polygonal in configuration and wherein said one surface of said body portion defines a recess of complementary configuration in which said sharpening bit is seated, said recess preventing inadvertent rotation of said bit.
 7. A sharpener for sharpening garden tools and the like comprising: a. an elongated member having an elongated generally planar body portion and having a pair of side margins which define the longitudinal axis thereof and a notch formed intermediate the length of one of said side margins, said notch being of generally V-shaped configuration with sidewall portions diverging outwardly from the base thereof and its axis extending substantially perpendicularly to said longitudinal axis defined by said side margins of said elongated member, said base being disposed adjacent the midpoint of said longitudinal axis, said elongated member having a pair of upstanding and longitudinally extending flanges along each of said side margins, the upstanding flanges of said flange pair being disposed on opposite sides of said notch and the flange pairs on opposite side margins being generally in alignment along the length of said body portion; b. a sharpening bit of generally polygonal configuration; and c. a fastener seated in said sharpening bit and in an aperture in said body portion adjacent said notch mounting said sharpening bit on one surface of said body portion with a side thereof extending over said notch base and only a portion of the depth of said notch to provide a surface spaced from the base of said notch and extending substantially parallel to said longitudinal axis of said elongated member, said surface being exposed for contact with a tool inserted in said notch, said notch and bit being cooperatively dimensioned to permit either side surface of a blade edge inserted into said notch to be brought into contact with a surface of said bit extending generally parallel to said longitudinal axis of said elongated member, whereby both side surfaces of a tool defining a cutting edge may be sharpened by contact with said overlying side without requiring reversal of either the tool or the sharpener.
 8. The sharpener of claim 7 wherein said flanges are generally upwardly turned relative to said body portion and said sharpening bit is mounted on the upper surface of said body portion. 